1. Field of the Invention
The present invention relates generally to infrared fiber optics and, more specifically, to wavelength and power scalable waveguiding-based infrared laser systems.
2. Description of the Prior Art
Scientific advancements are constantly improving the availability of laser sources. In the infrared range, lasers are used for a myriad of applications such as but not limited to medical, sensing, defense, characterization, etc. However, applications continually drive the need for higher power or broader range laser systems with optical mode characteristics. In particular, for certain applications, the valuable metric is not solely power or spectral range, but must include spatial homogeneity and divergence.
The near-infrared optical window is roughly defined as covering optical wavelengths from 0.8-2 μm. The mid-infrared optical window is roughly defined as covering optical wavelengths from 2-5 μm. The long-wave infrared range is roughly defined as covering optical wavelengths 5-30 μm. The development of a system architecture that functions in the infrared range (including mid-infrared or long-infrared) which provides for scaling of power and/or wavelength capabilities while providing a single output with appropriate spatial and divergence characteristics has been lacking.
Optical waveguides consists of a core surrounded by one or more claddings. Light travels in the core and is confined by the index difference between the core and cladding. Optical waveguides can be fabricated as fibers or planar devices.
Chalcogenide fiber is fiber composed of the chalcogen elements sulfur, selenium, and tellurium. Typically, other elements are added to stabilize the glass. Arsenic sulfide (As2S3), arsenic selenide (As2Se3), germanium arsenic sulfide, and germanium arsenic selenide are a few examples of chalcogenide glass.
Pushkarsky (U.S. Pat. No. 8,306,077) teaches a method for assembling a laser source based on laser emitters whose wavelengths are in the infrared (3-14 um) through the spatial combination of laser beams. The assembly of Pushkarsky involves a plurality of optical elements attached to a base plate and mechanically aligned to generate a specific geometrical arrangement prior to an optical lens. The use of externally mechanically aligned optical elements is sensitive to thermal and vibrational changes. This approach imposes a restriction on the design of the laser by imposing severe conditions for maintaining the pointing stability such as careful thermal management of over the entire laser assembly and mechanical vibration stability over the entire laser assembly.